volkswagen Workshop Repair Guides

Volkswagen Workshop Service and Repair Manuals

Checking signal from air conditioner compressor > < Checking control unit voltage supply
Motronic fuel injection and ignition system 08.95 ä
Motronic injection and ignition system
Checking signal from automatic gearbox

Special tools, testers and auxiliary items

  • ◆ Fault reader V.A.G 1551 or vehicle system tester V.A.G 1552 with cable V.A.G 1551/3
  • ◆ Test box V.A.G 1598/18
  • ◆ Hand multimeter V.A.G 1526 or multimeter V.A.G 1715
  • ◆ Adapter set V.A.G 1594
  • ◆ Current flow diagram

Test sequence

  • ‒ Connect fault reader V.A.G 1551 (V.A.G 1552) and select engine electronics control unit with the "Address word" 01. When doing this the engine must be running at idling speed.
    (Connecting fault reader and selecting engine electronics control unit .)
 
→ Indicated on display:
Rapid data transfer     HELP
Select function XX
  • ‒ Press keys 0 and 8 for the function "Read measured value block" and confirm entry with Q key.
 
→ Indicated on display:
Read measured value block     HELP
Input display group number XXX
  • ‒ Press keys 0, 0 and 8 for "Display group number 8" and confirm entry with Q key.
 
→ Indicated on display:
(1...4 = Display zones)
Read measured value block 8     ⇒
     1     2     3     4
  • ‒ Check the signals from automatic gearbox (display zone 2):

Display zones

1

2

3

4

Display group 8: Signals to engine control unit

Display

xxxx rpm

Text

Text

Text

Indicated

Engine speed

Driving range status

Air conditioner status

Air conditioner compressor status

Working range

800...6000 rpm

---

---

---

Specification

800...880 rpm

P and N: NEUTRAL
1, 2, 3 and D: ON

---

---

---

If specification is not attained => Page 24-114 , continuation

---

---

Continuation

If the display does not indicate as described:

  • ‒ Check the wiring between engine control unit (contacts 07, 11, 18 and 21) and gearbox control unit according to current flow diagram.

Checking signal from air conditioner compressor > < Checking control unit voltage supply